usb: gadget: udc-core: remove unused usb_udc_attach_driver()

Now when last user of usb_udc_attach_driver() is switched
to passing UDC name via usb_gadget_driver struct, it's safe
to remove this function

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/udc/udc-core.c

@@ -520,32 +520,6 @@ err1:
 	return ret;
 }
 
-int usb_udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
-{
-	struct usb_udc *udc = NULL;
-	int ret = -ENODEV;
-
-	mutex_lock(&udc_lock);
-	list_for_each_entry(udc, &udc_list, list) {
-		ret = strcmp(name, dev_name(&udc->dev));
-		if (!ret)
-			break;
-	}
-	if (ret) {
-		ret = -ENODEV;
-		goto out;
-	}
-	if (udc->driver) {
-		ret = -EBUSY;
-		goto out;
-	}
-	ret = udc_bind_to_driver(udc, driver);
-out:
-	mutex_unlock(&udc_lock);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
-
 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 {
 	struct usb_udc		*udc = NULL;

include/linux/usb/gadget.h

@@ -1121,8 +1121,6 @@ extern int usb_add_gadget_udc_release(struct device *parent,
 		struct usb_gadget *gadget, void (*release)(struct device *dev));
 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
-extern int usb_udc_attach_driver(const char *name,
-		struct usb_gadget_driver *driver);
 
 /*-------------------------------------------------------------------------*/